Heat exchanger coil assembly



Oct. 31, J, PRYB|L HEAT EXCHANGER COIL ASSEMBLY 3 Sheets-Sheet 1 Filed Sept. 28, 1964 lNVENTOR JOH N T. PRYB] L BY W A ATTORNEY 3 1967 J. T. PRYBIL HEAT EXCHANGER COIL ASSEMBLY 3 Sheets-Sheet 2 Filed Sept. 28, 1964 FIGB INVENTOR JOHN M-u T, PRYBI L AT TO RNEY Oct. 31, 1967 PRYBlL 3,349,842

HEAT EXCHANGER COIL ASSEMBLY Filed Sept. 28, 1964 3 Sheets-Sheet 3 FIG? 9 so FIGQ INVENTOR JOHN T PRYBIL BALM ATTORNEY FIGIO PRIOR ART United States Patent 3,349,842 HEAT EXCHANGER COIL ASSEMBLY John T. Prybil, Chicago, Ill., assignor to Vapor Corporation, Chicago, Ill., a corporation of Delaware Filed Sept. 28,1964, Ser. No. 399,772 1 Claim. (Cl. 165-163) This invention relates in general to steam generators, and more particularly to a heat exchanger for use in a steam generator, and still more particularly to a heat exchanger for cooling the return water from the steam separator and for preheating feed water before it enters the steam generator coils.

Heretofore, heat exchangers provided for use with steam generators have had short lives inasmuch as they would fail due to being subjected to vibration. More particularly, the coil of the heat exchanger would fail due to work-hardening and breaking that is caused from vibration.

Therefore, it is an object of the present invention to obviate the above identified difficulties and to provide an improved heat exchanger for use with steam generators.

Another object of this invention is in the provision of a heat exchanger for use with steam generators, wherein the coil of the exchanger is so constructed and mounted Within the casing of the exchanger so that vibration of the exchanger has little or no effect on the coil, thereby increasing the life of the coil by a substantial amount.

Still another object of this invention resides in the provision of a heat exchanger for use with a steam generator and having a coil so constructed as to improve the water flow therethrough, thereby substantially reducing clogging caused by lime deposit formations, and thereby adding substantial life to the exchanger.

A further object of this invention is to provide a heat exchanger for a steam generating unit and having a coil that is snugly received in the casing of the exchanger so as to substantially reduce, if not eliminate, the vibration of the coil, thereby greatly extending the life of the heat exchanger.

A still further object of this invention is in the provision of a heat exchanger for a steam generating unit including a casing and a coil therein, wherein the coil is provided with relatively short leads, thereby eliminating 3,349,842. Patented Oct. 31, 1967 employing the heat exchanger of the present invention;

work-hardening and breaking of the coil due to vibration.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a front elevational view of the heat exchanger in accordance with the invention, and showing some parts in dotted lines for purposes of clarity;

FIG. 2 is a bottom plan view of the heat exchanger of FIG. 1;

FIG. 3 is a partially sectional and partially elevational view of the coil for the heat exchanger;

FIG. 4 is a bottom plan view of the coil of FIG. 3;

FIG. 5 is an axial sectional view of a connecting L which is employed for connecting the coil to a connector fitting through the exchanger casing;

FIG. 6 is an axial sectional view of another connecting L also utilized in connecting the coil to the connectors extending through the casing;

FIG. 7 is a partially sectional view and partially elevational view of the outlet assembly of the coil of FIG. 3;

FIG. 8 is an elevational view of the for the coil of FIG. 3;

FIG. 9 is a partial block diagram of a steam generator and FIG. 10 is an elevational view, with some parts broken away for clarity, of a heat exchanger coil of the prior art.

Referring now to the drawings, the heat exchanger of the present invention is shown in FIGS. 1 and 2 and generally designated by the numeral 15. The heat exchanger includes a casing 16 having upper and lower sections 17 and 18. The sections 17 and 18 are somewhat dome-shaped, but facing each other. The upper section 17 includes a feed water inlet 19 arranged adjacent its peripheral edge, and a feed water outlet 20 positioned centrally thereof. The lower section 18 includes a drain valve 21, a return water inlet 22 and a return water outlet 23. The return water inlet 22 is arranged centrally of the section 18, while the return water outlet 23 is arranged along the peripheral edge of the section 18.

Referring now to FIG. 9, the heat exchanger 15 is shown diagrammatically how it is located and utilized with a steam generator. The feed water inlet 19 is connected to a feed water outlet 24 of a return tank 25, while the feed water outlet 20 of the heat exchanger is connected to the inlet 26 of the steam generator coils 27. The outlet 28 of the steam generator coils delivers steam to the steam inlet 29 of the steam separator 30. A combustor 31 provides the heat energy for the steam generator coils 27. The return water outlet 32 of the steam separator 30 is connected to the return water inlet 22 of the heat exchanger coil, while the return water outlet 23 of the heat exchanger coil is connected to the return water inlet 33 of the return tank 25. Thus, it is seen how the heat exchanger functions in a steam generator, wherein it cools the return water from the steam separator and preheats the feed water entering the steam generator coils.

Referring again to FIGS. 1 and 2, the casing sections 17 and 18 are suitably secured together by fasteners 34, and the casing has mounted therein a heat exchanger coil 35. Actually the return water inlet 22 and the return water outlet 23 are connected to the coil 35.

Referring now to FIGS. 3 and 4, the coil 35 includes a plurality of concentric layers of turns 36, 37, 38 and 39. The coil 35 is somewhat annular in shape and is provided with inclined outer concentric faces, and opposed end faces. The layers of turns are separated by sinuous spacers 40, and block spacers 41 are provided between the turns in the outer layer 39. The layers of turns together essentially define staggered rows of turns 42, 43, 44, 45, 46 and 47.

The turns of the coil 35 include a return water inlet 48 and a return Water outlet 49. As seen particularly in FIGS. 3 and 4, the return water inlet 48 and the return water outlet 49 are at the same end face of the coil, and the return water inlet 48 is also arranged at the inner concentric face, while the return water outlet 49 is arranged at the outer concentric face of the coil. Thus, the return water enters along the inner concentric face of the coil and moves toward the outer concentric face which is counter to the flow of the feed water which moves from the outer concentric face toward the inner concentric face in and around the turns of the coil 35.

Referring now to FIG. 8, an inlet assembly 50 is provided for connection to the return water inlet 48 of the coil 35, and this assembly includes an inlet connector 51, an L 52 and an L 53. The inlet connector 51 extends through an enlarged portion 54 of the lower casing section 18 and is held in place by a nut 55, FIG. 1. A fitting 56 is carried on the inlet connector 51 for further connection to other lines.

Both Ls 5-2 and 53 are preferably of a rigid material and preferably cast from bronze or the like, while the coil 35 is preferably copper tubing. The L 52 includes an end 57 that is telescopically received within an end 58 of the inlet connector 51, and an end 59 telescopically received in an end 60 of the L 53. At the joints of the L 52 and the L 53, and the L 52 and the inlet connector 51, suitable soldering sealingly secures the L 52 in position. As seen in FIG. 8, the soldering is indicated by the numerals 61 and 62. The L 53 also includes an end 63 that receives in telescopic engagement the return water inlet 43 of the coil 35. Suitable soldering 64, FIG. 4, secures the joint between the L 53 and the return water inlet of the coil. Thus the turn of the coil having the return water inlet 48 is not displaced from the end face of the coil, whereby the heavier constructed Us 52 and 53 serve to connect the return water inlet 46 directly to the inlet connector 51. Further, the leads from the inlet connector 51 to the return water inlet 48 of the coil are relatively short.

In FIG. 7, an outlet assembly 65, connectable to the return water outlet 49, includes an outlet connector 66 and an L 52. The end 59 of the L 52 is telescopically received within an end 67 of the connector 66, while the end 57 telescopes over the return water outlet 49. Soldering 68 seals the joint between the L 52 and the connector 66, while soldering 69 seals the joint between the L 52 and the return water outlet 49 of the coil '35. The outlet connector 66 extends through a boss 70 in the lower casing section 18, and is suitably held in place by a nut 71. A fitting 72 is provided on the outlet connector 66 for interconnecting sa-me to other lines. Thus the outlet assembly 65 defines a short lead between the water return outlet 49 and the exterior of the casing 16.

Referring now to FIG. 1, coil pads 73 are mounted within the upper casing section 17 against which the coil 35 rests, while coil pads 74 are mounted on the inside of the lower casing section 18 for supporting the other end of the coil 35. A retaining ring 75 is centrally mounted at the inside of the upper casing section 17 and coacts with the inner concentric upper end of the coil 35 to aid in holding the coil in place. The inlet and outlet assernblies serve to hold the other end of the coil 35 in position.

Referring now to FIG. 10, a heat exchanger coil generally designated by the numeral 76 is shown to represent the prior art and the weaknesses of the prior art, wherein the coil includes a return water inlet 77 and a return water outlet 78. The return water inlet 77 is connected directly to an inlet connector 79, while the return water outlet 78 is connected directly to an outlet connector 80. The return water inlet 77, a part of the tubing of the coil, is bent at 81 from the plane of the coil turns, while the return water outlet 78 is bent from the turns of the coil at 82. Thus, the portion of the tubing between the return water inlet 77 and the bend 81 constitutes a lead from the coil 76. Similarly the tubing between the return water outlet 78 and the bend 82 constitutes a lead from the coil. It is readily seen that these leads are relatively long, and due to vibration the areas of the tubing adjacent the bends 81 and 82 work-harden and eventually break causing failure of the coil. It is therefore seen that the present invention obviates this difficulty and that it materially shortens the leads from the coil to the connectors and also increases the strength of the leads thereby minimizing, if not eliminating, the problem of failure caused from work-hardening which is due to vibration.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claim.

The invention is hereby claimed as follows:

A heat exchanger for a steam generator for cooling the return water from the steam separator and for preheating the feed water delivered to the steam generator coils comprising, a casing having a feed water inlet and a feed water outlet, a coil in said casing including a plurality of turns arranged in concentric layers and staggered rows defining an annularly shaped coil having inner and outer concentric faces and opposed end faces, a return water inlet and a return water outlet defined at the terminal ends of said turns, said inlet and-outlet being at one of said end faces and lying within said end face, inlet and outlet return water connectors extending substantially parallel to the axis of the coil and substantially perpendicular to said turns thereof, and rigid connecting Ls extending between said connectors and the inlet and outlet of the coil, s aid connectors extending through said casing, said inlets and outlets arranged so that the flow of return water in the coil is counter to the flow of feed water in said casing, and means in the casing to snugly receive the coil including a plurality of coil pads and a retaining ring, said retaining ring being secured at the inner side of the casing and received slightly within one open end of the coil at the end face remote from the end face in which lies the coil inlet and outlet.

References Cited UNITED STATES PATENTS 2,501,012 3/1950 St. Clair 163 X 2,775,431 12/1956. Krassowski 165-178 X 2,805,048 9/1957 Angelery 165163 X FOREIGN PATENTS 670,026 1/1939 Germany.

ROBERT A. OLEARY, Primary Examiner.

FREDERICK L. MATTESON, JR., Examiner.

M. A. ANTONAKAS, Assistant Examiner. 

